The costs and benefits of safety cannot logically be separated from the costs and benefits of mobility. Although the value of life and the value of time are difficult to estimate, there are means available for approaching monetary values. Calculations are given for one well-known safety intervention: the US 55 mph speed limit.

This paper looks at the differences between the private firm and the public planner in timing investment in projects involving large sunk costs in growing markets. It shows that competition in the private sector will drive firms to invest earlier than the socially preferred date whilst a low ratio of private (producer) to public (producer plus consumer) benefits will cause them to delay relative to the socially preferred date. The paper looks at policy instruments for altering the private sector’s timing decision.

The paper examines arguments which suggest that the investment plans of the UK’s nationalised industries before the end of the 1970s were inadequately constrained by the control mechanisms then in place but the newly privatised utilities subject to price cap regulation have inadequate incentives to invest. Comparison of the likely social costs of underinvestment and overinvestment suggest that the former will generally be higher under existing regulatory mechanisms. The paper concludes by suggesting solutions to the dilemma posed.